Adding fonts (mac OSX 10.11.3)

I’m using Libre Office Vanilla Version: and for some reason the displayed fonts don’t include all my fonts held in my Font Book on my Mac. I’ve looked at the previous answers on the forum but they pertain to Windows… I’m very sorry too ask a daft question but firstly why can’t Libre Office read the fonts on my Mac and secondly how might I force it to? Is there a way of adding fonts manually to Libre Offie Vanilla?
Thanks very much in advance,